1. Field of the Invention
The invention relates to an original device for automatically extracting the end of a negative film from the cartridge which contains it, with a view to proceeding to develop it.
2. Discussion of the Prior Art
In a known manner, and most often, the negatives are stored in cartridges of generally cylindrical shape, comprising a rotation spindle along the axis of revolution of the cylinder, in the region of which spindle one of the ends of the negative is fixed. When the reel or the cartridge is ready for use, the free end of the negative film leaves the cartridge via a gate, extending a slot formed along the entire cartridge in the region of one of the generatrices of the cylinder.
Once all the negative film has been used, that is to say once the negative has arrived at the end of its travel, the cartridge is re-reeled in the conventional manner, the film then being entirely inside the cartridge. The abovementioned gate is partially closed off so as to make the inside of the cartridge tight especially to light.
In the context of negative film automatic developing and printing devices, there is the problem of extracting the end of this negative film from the cartridge. Currently, the procedure is most often carried out manually by means of a blade equipped with an adhesive, which is introduced through the gate, then by the intermediary of the slot inside the cartridge, to stick to the negative film and thus to pull it out.
Attempts have thus been made to automate this principle of a blade equipped with an adhesive, however, it was found that the reliability of this device was far from being compatible with industrial-scale use. Furthermore, such a device uses consumables, namely the adhesive, which is in the form of a film which unrolls after each use, the blade simply pushing this adhesive film inside the gate then the slot.
Another device is also known, which calls for a member equipped with two flexible tabs, which enable, after various operations, the end of the film to be gripped, and thus to be extracted. Once again, automation proves tricky, because one of these operations involved the noise generated by the clicking of the film being released from a tab.